Arming and sterilizing mechanism for mine systems



April .24, 1962 w. D. MouNcE ETAL 3,030,885

ARMING AND STERILIZING MECHANISM FOR MINE SYSTEMS Filed Dec. 8, 1950 FIG.1.

v INVENTORS. WHITMAN D. MOUNCE yEVERETT W. WERTS 5 Sheets-Sheet 1 A ril 24, 1962 w. p. MOUNCE ETAL 3,030,885

ARMING AND STERILIZING MECHANISM FOR MINE SYSTEMS Filed Dec; 8, 1950 5 Sheets-Sheet 2 3' flln 2x, In? u. fill O 50: g 3 28 co 6 z N II) o N zlr- 5E u. w 05 W '2 6 I m 2 o E o v J i 9, 5 LL.

INVENTORS. WHITMAN D. MOUNCE y EVERETT W. WERTS ///fl/ZM M Arrra.

mine.

United States Patent 3,030,885 ARMING AND STERILIZING MECHANISM FOR MINE SYSTEMS Whitman D. Mounce, 3623 Overbrook Lane, Houston,

Tex, and Everett W. Werts, 110 Wilshire Ave., Michigan City, Ind.

Filed Dec. 8, 1950, Ser. No. 199,906 Claims. (Cl. 102-18) (Granted under Title 35, U8. Code (1952), sec. 266) This invention relates generally to the art of arming and sterilizing certain types of ordinance devices which contain high explosive charges such, for example, as naval mines.

More particularly the instant invention is directed to a new and novel apparatus for arming and sterilizing naval mines and analogous ordnance equipment by exploding a series of depth charges, shells, bombs, or by transmitting other suitable impulse signals in a predetermined time sequence thereby causing the actuation of mine arming switches which are connected in a timing circuit which has been preset for the shock or impulse sequence.

Heretofore, mechanical timing systems for marine mines have been utilized in which an inertia element is commonly employed for preventing the closure of the firing circuit of the mine until a shock is received. These systems have not been found to be entirely satisfactory in all conditions of service because these systems are comparatively complex and involve many mechanical elements which must be adapted for movement relative to one another which, in turn, subject the entire mine to the possibility of mechanical failure at many points throughout the mechanism. Another disadvantage of these mechanisms of the prior art is that the mine cannot be selectively armed, sterilized or disabled from a remote control station at any predetermined time. This matter is of importance in the consideration of naval mine jwarfare because complete control of a mine field employing such mines is impossible to attain in the absence of such features and, therefore, the field cannot be selectively armed, sterilized or disabled in accordance such as switches controlled by step by step motors, ro-

tary motors, clock movements, escapement devices, dash pots and the like. Such time measuring devices have not proved altogether satisfactory in service for the reason that mechanical devices, because of the relatively large mass of the elements and the necessity of employing moving parts therein, are particularly susceptible to damage or injury thereto as a result of the shock or blow which the time measuring device receives at the moment the. mine in which it is mounted strikes the water or the bed of the seat at the time of planting of the Such shocks are particularly intense in the case where the mine is launched from an aircraft in flight and various expedients, such as attaching a parachute fo .the mine or dropping of. the mine from a low altitude,

havebeen resorted to in order-toreduce the shock to marine type mine maybeselectively armed, sterilized or disabled by producing a predetermined number of underwater shock waves 'or impulses in' a predetermined ice sequence and at predetermined time intervals and wherein the system employs electronic components to effect various circuit functions. A different combination of shock Waves or impulses is required for sterilizing the mine than that required for arming the mine.

The timing sequence for arming and sterilizing can be independently adjusted over a wide range and can be readily set at any time before the mines are planted such, for example, as at the time of manufacture or on board ship. The complexity of the timed sequence of impulses or shock waves is suflicient so that the operation of the mechanism by trial and error without knowledge of the setting is exceedingly diflicult. This feature prevents unintended arming or sterilization through detonation of a mine field incorporatng the presentinvention thereby preventing the mine from being swept or sterilized by enemy forces who do not know what impulse signals correspond to the predetermined coded pattern.

One of the objects of the present invention is to provide a new and improved demolition device for use as a component of a mine for arming and sterilizing the mine in response to underwater coded signals which may be initiated at a remote distance from the mine and which will disable the mine should a spuriously timed impulse be received thereby while the mechanism is in operation.

Another object is to provide means for arming a mine in response to impulse signals arranged in predetermined time spaced relation received through the water surrounding the mine.

Another object is to provide means for sterilizing an armed mine in response to predetermined impulse signals arranged in predetermined time spaced relation with one another.

A further object is to provide a new and improved demolition device responsive to a predetermined coded signal whereby a mine field employing mines having such devices is prevented from being swept by enemy forces in the field.

Another object is to provide a mine mechanism which is capable of temporarily disabling the mine in which it is employed upon receipt of a spuriously timed impulse received during operation of the mechanism.

A still further object is to provide a new and improved impulse responsive device for controlling a plurality of circuits after a starting impulse has been received in which the circuits are closed selectively in accordance with the time spaced characteristics of a plurality of additional impulses received by the device.

A still further object is to provide a new and improved demolition device having a plurality of control circuits selectively responsive to coded impulses which will be economical to manufacture, reliable in operation and which possesses all of the qualities of ruggedness and durability in service.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is an elevation view of a portion of a marine mine with parts thereof being broken away to show the manner in which the arming and sterilizing device of the instant invention may be mounted therein;

FIG. 2 is a plan view of the structure disclosed in FIG. 1;

FIG. 3 is a schematic showing of the control circuit used in the mine arming and sterilizing mechanism in accordance with one form of the instant invention in which a normally closed chatter switch is used;

FIG. 4a and 4b are charts showing the arming and sterilizing cycles of operation, respectively, of the components comprising the device as shown in FIG. 3 for a predetermined coded impulse pattern;

FIG. 5 is a schematic showing of the control circuit used in the present invention in accordance with another form thereof in which a normally open chatter switch is used; and

FIGS. 6a and 6b are operation charts for the device as shown in FIG. 5 and similar to that of FIGS. 4a and4b.

Referring now to the accompanying drawings in which like reference numerals are employed in designate like parts, and more particularly to FIGS. 1 and 2 thereof in which reference numeral 11 generally designates a mine similar to that disclosed in FIG. 1 of the application by Whitman D. Mounce et al. for Mine Firing Control System, Serial No. 500,399, filed August 28, 1943, and in which the arming and sterilizing mechanism of the present invention is incorporated to replace the arming clock disclosed therein. The mine 11 is provided with a casing 12 having fins 13 secured thereto in any suitable manner for the purpose of directing and steering the mine during the launching thereof within a body of water. The mine casing 12 is filled with an explosive charge 14. A plug 16 is inserted into the opening 15 fiush with the outer surface of the casing 12 and is secured in position in any suitable manner such, for example, as by welding.

Plug 16 is provided with a stepped recess 17 the respective steps or shoulders thereof serving as means upon which components, hereinafter described, of the arming and sterilizing mechanism are mounted. Shoulder 18 is provided with a plurality of threaded holes 19 adapted to receive bolts 21. The inner portion of shoulder 18 is provided with an upwardly extending circumferential flange 22 having an annular seal 23 of any suitable rubber-like material bonded thereto.

A cartridge 24 is employed as a housing for certain components of the circuit and mechanisms shown in FIGS. 3 or 5, respectively, such as transfer switch assemblies, an impulse responsive switch, tubes, resistors, condensers, a motor, and earns driven by the motor, to be more fully described hereinafter. Cartridge 24 is closed at its top, as viewed in FIG. 1, .by a circular plate 25 which is held in clamping engagement against the upper end of the cartridge by bolts 26 which extend through the cartridge and coact with the nuts 27. Bolts 21 are passed through holes which are in arcuate spaced relationship to one another in the outer periphery of plate 25 and are threaded into the threadedholes 19 to clamp the lower face of plate 25 in a fluid-tight engagement with the annular seal 23.

Another cartridge 28 contains the remainder of the components shown in FIGS. 3 or 5, respectively, such,

for example, as a relay, a condenser, a heat coil relay and a fuze switch as will more fully appear as the description proceeds. The upper end of this cartridge is closed by a flange 29 secured in any suitable manner to the cartridge and bolted to shoulder 31 of the recess 17 by bolts 32.

The components of cartridge 24- are connected to.those of cartridge 28 by a shielded cable 33, and the outlet side .of the components housed within cartridge 28 is connected to mine apparatus, not shown, by a shielded cable 34.

.Any suitable impulse responsive pickup device such, for example, as one incorporating a diaphragm 5, FIG. 2, may be operatively connected to the impulse responsive switch whereupon impulses such as pressure waves transmitted through the. surrounding water and received 'by' the pickup device will cause the switch to be opened in the system disclosed in FIG. 3 and to be closed in that shown in FIG. 5, for the reasons appearing hereinafter. Such aswitch suitable for the purpose may begenerally similar to that disclosed and claimed in the .copending applicationof Harry H. Hall et al. for Chatter Switch, Serial No. 598,351, filed June 8, 1945, now Patent No. 2,969,440.

Reference is now made to FIG. 3 wherein the numeral 35 designates an electric timing motor of any suitable design connected through contacts 36 and 37 of a relay, shown generally at 38, and terminal 39 to any suitable source of power such, for example, as a 12 volt battery, not shown. It will be understood that such a source may be readily obtained from an additional tap on the battery 26 disclosed in the application for Mine Firing Control System by Whitman D. Mounce et al., Serial No. 594,133, filed May 16, 1945, since the instant invention is used in conjunction with a portion of the system disclosed therein, as will be more readily appreciated from an understanding of the description appearing hereinafter. The timing motor 35 drives shaft 41 at any desirable speed for rotation such as one-half revolution per minute, for example, through the employment of a gear box 42. Five notched cams -43, 44, 45, 46, and 47 are mounted on shaft 41 for rotation therewith. It will be understood that each cam may be provided with any desirable number of notches, only one notch on each cam being shown. The notches are denoted by numerals 48, 49, 51, 52, and 53, respectively. It will be observed, from an inspection of FIG. 3, that each cam shown therein has been turned approximately about a vertical axis in order that the configuration thereof may be more clearly shown. Each cam operates a deck of switches in a manner to be more fully understood as the description proceeds. The predetermined time sequence of shocks or impulses which is required to actuate the mechanisms shown in FIGS. 3 or 5 is determined by the particular rotational settings of the cams 43, 44, 45, 46, and 47 on shaft 41.

The relay 38 is provided with a coil 54 having any suitable resistance such, for example, as one having a resistance of 11,500 ohms. This relay is a modified telephone type relay which has been developed to withstand high accelerations encountered in mine applications. In addition to controlling the starting of the timing motor 35, relay 38 also functions to operate the heat coil relay, generally designated by numeral 55, which is also another type of telephone relay device modified for mine applications and is used in the present invention to close the arming circuits of the mine. The terminals 56', 57, 58, and 59 of the arming switches '61 and 62 are normally maintained in an open circuit position by a metal plunger 63 to which one element of each arming switch is connected and which is bonded in a fusible alloy 64 contained within a metallic tube 65. A heater coil 66 surrounds the metallic tube 65 whereby current passing through the coil 66 generates heat which melts the fusible alloy. The melting of the fusible alloy causes the plunger '63 to move further into the tube 65 thereby permitting the switches 61 and 62 to close. For further details of the construction and operation of heat control relays of this type, reference may be made to the copending application of John F. Toomey et al. for Heat Controlled Relay, Serial No. 525,610, filed March 8, 1944, now Patent No. 2,961,958. The terminals 56, 57, 58, and 59 are connected to the arming. circuits of any suitable rnine firing system such, for example, as in the arming circuit of the system shown in FIG. 1 of the application for patent having the Serial No. 594,133, hereinbefore identified. Although itheinventions disclosed and claimed in the hereinbefore identified applications for patent by Whitman D. Mounce form no part of the present invention, references are made thereto for the purpose of describing the manner in which the instant invention may be, advantageously. utilized therewith to form a complete mine system. 7

'In the specific. example of the present invention, as disclosed in FIG. 3, a chatter switch 67 which is normally closed is responsive to a shock .or impulse received by the diaphragm 35, FIG- 2, from the surrounding water and is thereby actuated to the, open position thereof for the purpose of momentarily passing current from a suitable source of power, connected to terminal 95, to certain of the switch assemblies shown generally at 68, 69, 71, 72, and 73. Such a source of power may be, for example, the same battery which supplies current to actuate motor 35.

The tubes 74, 75, 7'6, 77, and 78 may be of any suitable type such, for example, as cold cathode tubes. The grids of tubes 74, 75, 76, 77, and 78 are connected to ground through high resistances, the grids of tubes 75, 76, and 78 being connected through the resistors 79, 81, and 82, respectively, each of which has a resistance of 10 megohms, the grid of tube 74 being connected to ground through resistors 83 and 84 of 8 megohms and /2 megohm, respectively, and the grid of tube 77 being connected to ground through the eight megohm resistor 85 and the megohm resistor 86' in series. These resistors maintain the grids of tubes 7476 and 77--78 at ground potential when the respective control circuits therefor are open at the cam switches 68, 69, 72, and 73. The capacitors 87, 88, 89, 91, and 92 which are connected between the grids of tubes 74, 75, 76, 77, and 78, respectively, and ground function to supply current when the grids of these tubes fire and insure that the discharge transfers to the plate circuits. Resistors 90 and 97 have resistances of 8 and 10 megohms, respectively. The capacitors 87, 08, 89, 91, 92, and 93 may be of any suitable type which will accomplish the desired results, two types having been utilized in the specific embodiment of the present invention as disclosed in FIG. 3. The capacitors 87, 88, 89, 91, and 92, as disclosed herein, are paper condensers having a capacitance in the order of 0.0001 microfarad and a rating of 300 volts or higher, and capacitor 93 is of the electrolytic type and has a capacitance in the order of 125 rnicrofarads. The resistors shown in the embodiments of my invention, disclosed herein, are all of the /2 watt carbon type.

. In order that the embodiment of the present invention, as shown in FIG. 3, may be more fully understood the principles of operation thereof will now be described with reference being directed to FIGS. 3 and 4 of the drawings.

The system, as shown in FIG. 3, is in the neutral or initial position thereof to which it returns after each cycle of operation wherein the chatter switch 67 is closed and the follower 94 of cam 43 is positioned in the notch 48. The condenser 93 is charged to any suitable voltage such, for example, as 141 volts from the source of power connected to terminal 112 through conductor 113, contacts 114 and 115, conductor 116 having a resistance 117 therein, with the other side of the condenserbeing connected to ground. A voltage divider comprising resistors 97 and with chatter switch 67 interposed therebetween is connected between terminal 95 and ground 106. Point 100 in the divider is connected by way of conductor 98, contacts 99 and 101, and conductor 102 to the grid of tube 74. The resistor 20 is of such low value as to apply an insufficient voltage to tube 74 to cause the tube to be fired when the chatter switch is closed. In the specific example, herein disclosed, the voltage at point 100 is R20 2 202 Xm-202 X gm-34 VOlllS where R20=resistance 20 and R97=resistance 97.

When the chatter switch is opened, the voltage at point 100 and at the grid of any particular tube to which it is connected through the respective switch assembly rises as the grid condenser of the tube is charged until the tube fires. The timing motor starting circuit comprises three paths. The first path includes terminal 95, conductor 96, resistor 97, conductor 98, contact 99, contact 101, conductor 102 and condenser 87 connected to the grid of tube 74. The second path is traced from terminal 112 by way of conductor 113, contacts'119 and 118, and conductor 121 to the anode and'cathode of tube 74, and

thence through coil "54 to ground. The third path, which traced from the source of power connected to terminal 39, conductor 103, contacts 37 and 36, conductor 104, motor 35, conductor 105, and ground 106, is open between contacts 36 and 37 of relay 38. The timing motor running circuit comprising the source of current connected to terminal 39, conductor 103, conductor 107, contacts 108 and 109, conductor 111, motor 35, conductor 105, and ground 106' is open at contacts 108 and 109. It will be observed that the grid control circuits of the other tubes are all open at the respective transfer switches thereof.

When the chatter switch 67 opens in response to a shock or impulse received by the impulse responsive device 5, FIG. 2, the tube 74 is tired whereupon relay 33 is energized and contact 37 is moved into conducting relationship with contact 36 to complete the aforetraced third path of the motor starting circuit from terminal 39 to the timing motor. Within a few seconds such, for example, as three to six seconds after the timing motor has been started the rotation of cam 43 causes the follower 94 to rise out of notch '48 and operate the switch assembly 68. Upon an inspection of this switch assembly it will be observed that contacts 108 and 109 close prior to the opening of contacts 118 and 119 in the plate circuit of tube 74, the latter contacts, upon the opening thereof, causing tube 74 to be extinguished and the relay 38 to be de-energized. The transfer of contact 114 from contact 115 to contact 120 opens the charging circuit to the condenser 93 and closes the plate circuit to the recording tubes and 76, respectively. Similarly, the transfer of contact 99 from contact 101 to contact 110 disconnects point 100 from the grid circuit of tube 74 and connects point 100 through contacts 99 and 110, 123 and124, 125 and 126, 127 and 128, and 129 and 131 to the grid of tube 78.

Should the chatter switch open in response to a shock or impulse when the grid of tube 78 is connected to point 100, in the manner hereinbefore mentioned, the tube 78 will be fired and the condenser 93 discharged. When condenser 93 is discharged under these circumstances, it will not recharge until the mechanism returns to the neutral or initial position thereof at the end of the timing cycle because the charging circuit to condenser 93 is open at contacts 114 and 115. Therefore, the firing of tube 70 disables the mechanism for either arming or detonating the mine for the remainder of the particular cycle in which this tube is fired. It will be readily understood from the foregoing description that a shock occurring at any time when none of the cam followers are in their respective notches will cause tube 78 to be fired and the mechanism to be disabled for the remainder of the cycle.

When cam 44 has rotated to the position in which its follower 132 drops into the notch 49, contact 123 is disconnected from tube 78 and connected to the grid of tube 75. The opening of the chatter switch 67 in response to a shock or impulse during that time in which the follower of cam 44 is in the notch 49 causes the firing of tube 75. The plate current of tube 75 is sustained through the cathode resistor 84 thereof so that the cathode .oftube 75 is maintained at a potential of any suitable magnitudesuch, for example, as 50 or 60 volts above ground. This voltage which is applied to the grid of tube 74 from the cathode of tube 75 through resistor 83 is not sufiicient to fire the tube-74. Therefore, if the second shock or impulse of the arming cycle occurs at the proper time so that the follower 132 is engaged with notch 49 of cam 44, this shock or impulse merely will be recorded by tube 75.

Upon further rotation of shaft 41, the follower 133 of cam 45 moves into the notch 51 thereby closing contacts 125 and 134 to connect the center tap voltage divider comprising resistors 83 and to point thereby causing,-when chatter switch 67 opens in response to a third impulse of the arming cycle, a substantial rise in the voltage on the grid of tube 74- to such an extent that the grid will be triggered. In the specific example, hereinbefore mentioned, the voltage on the grid of tube 74 rises toward i would be impressed by the third impulse upon the grid of tube 74 which is insufiicient to fire tube 74. When the tube 74 is triggered, then, if condenser 93 has not been previously discharged by the firing of tube 78, the condenser is now discharged by the firing of tube 74 through contacts 140 and 150 and thence through tube 74 and the coil of the relay 38 which momentarily energizes the relay and closes the relay contacts 30 and 46. The closing of relay contacts 30 and 4t) completes the circuit of the heat coil relay 55 from terminal 39 by way of conductor 163, contacts 40 and 30, conductor 160, contacts 170 and 180 to the heat coil 66 to thereby operate the heat coil relay 55 which, in turn, closes the arming switches 61 and 62. Thus if the second impulse of the arming sequence is recorded by tube 75 and the third impulse occurs While the follower 133 of cam 45 is in the notch 51, then the mechanism arms the mine providing it has not been disabled by an improperly timed impulse, as hereinbefore described.

After the arming switches have been closed shaft 41 continues to rotate until the cams have returned to their initial positions at which time condenser 93 is recharged, and upon another impulse being received by the impulse responsive device, the motor Starting and the motor running circuits are again closed, as hereinbefore described. A predetermined time interval after the first impulse of this subsequent cycle is allowed to pass so as to enable cam 46 to be rotated to such a position that notch 52 is engaged by the follower of transfer switch 72. If the next shock of the sterilizing cycle occurs while the follower of cam 46 is in the notch 52 then the shock is recorded by the lighting of tube 76. Should this shock be followed by another shock while the follower of cam 47 is in the notch 53 then the grid of tube 77 is triggered and tube 77 discharges condenser 93 through the detonator, not shown, of the mine firingcircuit connected to the detonator terminals 134 and 135, providing condenser 93 has not been previously discharged by an improperly timed shock. As a specific example of the manner in which terminals 134 and 135 may be connected into a detonator firing circuit, it will be understood that these terminals may be connected across the primary coil 64 of transformer T4 disclosed in the application for patent having the Serial Number 594,133, fully identified hereinbefore.

At the end of each cycle which may be of any desired time period such, for example, as a period of 120 seconds, the follower 94 of cam 43 drops back into the notch 48 and stops the timing motor 35. The next shock or impulse which reaches the mine starts a new' cycle. It will be understood that the sequential operation of tubes 76-77 is generally similar to the sequential operation of tubes 7574, and, therefore, the operating circuits therefor are not traced in detail.

The embodiment of the present invention as disclosed in FIG. 3 may be substantially simplified by the use of a normally open chatter switch instead of one which is normally closed, such a system being shown in FIG. as

embodiment will suflice for a complete understanding thereof.

Initially, the source of power connected to terminal 136 serves to energize condenser 137 through conductor 138, contacts 139 and 141, resistance 142, and conductor 143. When the first impulse is received through the surrounding water by any suitable impulse responsive device such, for example, as the diaphragm 5 of FIG. 2, the normally open chatter switch is closed, potential on conductor 138 is applied by way of the switch, contacts 151 and 144 and thence by way of conductor 153 to the grid of tube 146 to render this tube conducting and to thereby energize relay 147 which closes contacts 148 and 149 to complete the motor starting circuit. For purposes of disclosure, terminals 136 and 156 may be connected in any suitable manner to battery 26 of the application for patent having Serial No. 594,133 similarly as described hereinbefore in regard to the terminals 39, 95, and 112 in the embodiment illustrated in FIG. 3. However, it will readily be understood by those skilled in the art that these terminals may be connected to any suitable source of power, combined or separate. Upon closure of the motor starting circuit, the motor 159 causes the actuation of the gear reduction unit 162 and the rotation of shaft 163. The shaft 163 is provided with a notched cam 164 and four lugged cams 165, 166, 167, and 168, respectively.

'The rotation of cam 164 causes the follower 169 of the switch assembly, shown generally at 171, to rise out of the notch 172 thereby to close the motor running circuit which comprises the source of power connected to termitube 186 which will be fired to discharge condenser 137 and thereby disable the mechanism for the remainder of the cycle should an improperly timed impulse cause the chatter switch 145 to close. This disabling circuit is opened four times during the remainder of the cycle by the sequential actuation of switch assemblies 187, 188, 139, and 191, respectively. Prior to actuation of switch assembly 187 potential is placed on the plates of the two recording tubes .192 and 193 by way of conductor 138, contacts 139 and 194 and conductor 195.

Upon furtherrotation of cam to such an extent that the lug 196 actuates switch assembly 137, contacts 177 and 197 become engaged with one another. If the chatter switch is closed while these contacts are engaged, the tube 192 is fired thereby to apply a bias or an insuflicient potential to tube 146 to fire this tube. Tube 146 is fired and condenser 137 discharged when the chatter switch 145 is closed in response to an impulse being received by the impulse responsive device during the period that the cam follower of switch assembly 188 is on the lug of cam 166. The firing of tube 146 may be considered in two stages the first of which includes the application of a potential suflicient to fire the tube to the grid thereof from the source of power connected to terminal 136 through conductor 138, conductor 202, switch 145, contacts 151 and 152, contacts 177 and 178, contacts 179 and 203 of switch assembly 188 which is actuated concurrently with the closure of switch 145, conductor 204, resistance 205 and conductor 201. The second stage considered in the firing of tube 146 in the discharge of condenser 137 through conductor 143, conductor 206, contacts 207 and 208, conductor 299, which is connected to the plate of tube 146. The discharge of condenser 137 through tube 146 enengizesrelay 147 thereby closing contacts 211 and 212 tor actuate the arming switches 213 and 214, respectively, by the flow of current from the source of power connected to terminal 156 through conductor 157, con- 9. tacts 211 and 212, conductor 215, contacts 216 and 217, conductor 218, and the high resistance coil 219 of the heat coil relay 221 to ground 155. Upon completion of this cycle, the follower of switch assembly 171 falls once again into the notch 172 of cam 164 to thereby open the motor running circuit and stop the rotation of motor 159. While the respective cams are in their initial position, condenser 137 is recharged and potential is applied to the plate of tube 146, as hereinbefore stated. The mechanism of FIG. is now ready to commence a new cycle. The arming switches 213 and 214may be connected into another system similarly as were the arming switches 61 and 62 of the embodiment illustrated in FIG. 3.

When a first impulse in a subsequent cycle is received through the surrounding water by the impulse responsive device which is operatively connected to the chatter switch 1 45, the motor starting circuit is closed, the cams are rotated, and the motor running circuit is closed, in the manner hereinbefore described for the first or arming cycle of the mechanism. A sufficient interval of time is allowed to lapse before the second impulse is transmitted in order that cam 167 will have rotated a sufl'icient amount to have actuated switch assembly 189. Simultaneous receipt of the second impulse and the actuation of switch assembly 189 causes tube 193 to be fired by the source of power connected to terminal 136 by reason of the current therefrom flowing through conductor 138, conductor 202, switch 145, contacts 151 and 152, contacts 177 and 178, contacts 179 and 181, contacts 182 and 190, and conductor 222 to the grid of tube 193. The firing of tube 193 applies a potential to the grid of tube 223 through resistor 224, and conductor 225, it being understood, however, that this potential is insufficient to trigger tube 223. Upon simultaneous actuation of switch 145 as a result of the impulse responsive device having received an impulse from the surrounding water and the actuation of switch assembly 191, suflicient potential is applied to the grid of tube 223 whereupon this tube is fired to discharge condenser 137 across the detonator terminals 226 and 227. The tube 223 is caused to fire by reason of an additional potential being supplied to the grid thereof by current flowing from the source of power connected to terminal 136 through conductor 138, conductor 202, switch 145, contacts 151 and 152, contacts 177 and 178, contacts 179 and 181, contacts 182 and 183, contacts 184 and 228, conductor 229, resistance 231, and conductor 225. The detonator contacts 226 and 227 may be connected to any suitable detonator system such, for example, as that referred to in connection with the disclosure of the embodiment shown in FIG. 3. Thus it will be observed that arming occurs in one cycle while sterilization through detonation occurs in a subsequent cycle. Should a spurious impulse cause switch 1M5 to close, the mechanism is disabled for the remainder of the cycle in which it is operating.

It will be clearly apparent to those skilled in the art that the cams disclosed herein may be set for any desired distribution of the arming and sterilizing impulses within the chosen time period. The width of the notches and lugs in the respective cams determines the length of time the mechanism is receptive-to each impulse.

It will also be apparent that in certain circuit arrangements diode tubes may be used instead of the trigger type tubes herein disclosed.

While the invention has been described with reference to certain preferred examples thereof which give satisfactory results, it will be understood by those skilled in the art to which'the invention pertains, after understanding the invention, that various changes and modifications may be made Without departing from the spirit and scope of the invention, and it is my intention, therefore, to cover in the appended claims all such changes and modifications.

The invention herein described and claimed may be manufactured and used by or for the Government of the 10 United States of America for governmental purposes without payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a mechanism for arming and sterilizing a mine in response to impulses received in a predetermined sequence, the combination of first, second, third, fourth and fifth trigger type electron discharge devices, timing means operable in unit cycles including first, second, third, fourth and fifth switch means operated in predetermined time sequence during a complete cycle of operation thereof, a chatter switch operable in response to impulses received through the surrounding water, means including the chatter switch, said first switch means and said first discharge device for setting said unit cycle timing means in operation when the chatter switch operates in response to the first impulse received thereby in each cycle of operations, a relay operatively connected in the discharge path of said first discharge device and having a pair of normally open contacts which are closed when the first discharge device is conducting, a condenser, means including the first switch means for charging the condenser prior to each cycle of operation of said unit cycle timing means, an electroresponsive lock-in type arming device, means including the first and second switch means, the second electron discharge device, and the chatter switch for rendering the second discharge device conducting when the chatter switch is operated in response to a second impulse concurrently with operation of said second switch means, means effective during conduction of said second discharge device for applying a biasing voltage to said first discharge device insufficient to render the first discharge device conducting, means including the first, second and third switch means and the chatter switch for increasing said biasing voltage to a value sufiicient to trigger said first device when the chatter switch operates in response to the third impulse concurrently with operation of said third switch means, means including said condenser, said third switch means, said first discharge device and said relay connected in series circuit for operating the relay by energy discharged from the condenser as said first discharge device is triggered, means including said normally open contacts and the third switch means connected to the arming device for operating the arming device as said contacts close thereby to arm the mine during a first cycle of operation, means including the first, second, third and fourth switch means, the third discharge device, and the chatter switch for rendering the third discharge device conducting when the chatter switch and the fourth switch means are operated concurrently as the chatter switch operates in response to a second impulse received thereby in a subsequent cycle of operation of said unit cycle timing means, means effective during conduction of said third discharge device and including a second resistor connected in the discharge path thereof for applying a second biasing voltage to the fourth discharge device insufiicient to render the fourth discharge device conducting, means including the chatter switch, said second resistor and all of said switch means for increasing said second biasing voltage to a value sufficient to trigger said fourth discharge device when the chatter switch operates in response to a third impulse in a subsequent cycle concurrently with operation of the fifth switch means, a mine detonator,

acircuit connected in the discharge path of the fourth discharge device for series connection with the mine detonator, means including said detonator circuit, said fourth discharge device, and said condenser in series circuit for firing the detonator by energy discharged from the condenser as the fourth discharge device is rendered conducting thereby to sterilize the mine by detonation thereof, means including the chatter switch, all of said switch means, and the fifth discharge device for rendering the fifth discharge device conducting when the chatter switch operates in response to an impulse received in 3.1 time sequence different from the impulses of said first and subsequent cycles, and a circuit including the condenser and the fifth discharge device in series therewith for discharging the condenser therethrough when the fifth discharge device is rendered conducting to thereby disable the mechanism for the remainder of the cycle.

2. In a mechanism for arming a mine in response to impulses received in a predetermined sequence the combination of first, second, and third trigger type electron discharge devices, timing means operable in unit cycles including first, second, and third switch means operated in predetermined time sequence during a complete cycle of operations thereof, a chatter switch operable in response to impulses received through the surrounding water, means including the chatter switch, said first switch means and said first discharge device for setting said unit cycle timing means in operation when the chatter switch operates in response to the first impulse received thereby, a relay operatively connected in the discharge path of said first discharge device and having a pair of normally open contacts which are closed when the first discharge device is conducting, a condenser, means including the first switch means for charging the condenser prior to each cycle of operations of said unit cycle timing means, an electroresponsive lock-in type arming device, means including the first and second switch means, the second electron discharge device, and the chatter switch for rendering the second discharge device conducting when the chatter switch is operated in response to a second impulse concurrently with operation of said second switch means, means including a first resistor connected in the discharge path of the second discharge device and effective during conducting of said second discharge device for applying a triggering voltage to said first discharge device insnfiicient to render the first discharge device conducting, means including the first, second, and third switch means and the chatter switch for increasing said triggering voltage to a value sufiicient to render said first discharge device conducting when the chatter switch operates in response to the third impulse concurrently with operation of the third switch means, means including said condenser, said third switch means, said first discharge device and said relay connected in series circuit for operating the relay by energy discharged from the condenser as said first discharge device is rendered conducting, and means including said normally open contacts and the third switch means connected to the arming device for operating the arming device as said contacts close thereby to arm the mine.

3. In a mechanism for sterilizing a mine in response to impulses received in a predetermined time sequence, the combination of first and second trigger type electron discharge devices, timing means operable in unit cycles including first and second switch means operated thereby in predetermined time sequence during a cycle of operation thereof, a chatter switch operable in response to impulses received through the surrounding water, circuit means including the chatter switch for setting said unit cycle timing means in operation when the chatter switch operates in response to the first impulse received thereby, a condenser, means operatively connected to said unit cycle timing means for charging the condenser prior to each cycle of operation of said unit cycle means, means including the first and second switch means, the second discharge device, and the chatter switch for renderingthe first discharge device conducting when the chatter switch and the second switch means are operated concurrently as the chatter switch operates in response to a subsequent impulse received thereby in concurrence with the predetermined time sequence of operation of said second switch, means eifective during conducting of said first discharge device and including a resistor connected in the discharge path thereof for applying a biasing voltage to the second discharge device insufiicient to render the second discharge device conducting, means including the chatter switch, said resistor and both of said switch means for increasing the biasing voltage to a value sufiicient to render said second discharge device conducting when the chatter switch operates in response to a third impulse concurrent with operation of the second switch means, a mine detonator, a circuit connected in the discharge path of the second discharge device for series connection with the mine detonator, and means including said detonator circuit, said second discharge device, and said condenser in series circuit for firing the detonator by energy discharged from the condenser as the second discharge device is rendered conducting thereby to sterilize the mine by detonation thereof.

4. A mine mechanism of the character disclosed comprising, in combination, a plurality of sources of power, a pressure responsive chatter switch connected between a first of said sources of power and ground, a plurality of cam operated transfer switch assemblies having transfer switches oper-atively interconnected in series relationship for actuation in a predetermined time sequence, a first normally closed switch of the first of said assemblies being connected to the connection between said first source and the chatter switch, a timing motor, a plurality of switch actuating cams connected to said motor for rotation thereby at a predetermined rate, to actuate said switch assemblies in said predetermined time sequence, a second normally closed switch of said first of the assemblies being connected to a second of said sources of power, a condenser, a charging circuit for charging said condenser from said second source of power and including said second switch of said first assembly initially connecting the condenser thereto, a motor starting circuit operable from a third of said sources of power and including a pair of normally open contacts and the motor, a relay for closing said normally open contacts when the relay is energized, a relay circuit including a third normally closed switch of the first assembly for energizing the relay from said second source when the relay circuit is openatively energized by said first source through said first normally closed switch in concurrence with the operation of the chatter switch in response to a first impulse transmitted through the surrounding water, a motor running circuit operable from said third source of power and including a normally open switch of the first of said assemblies and the motor, said third normally closed switch and said first normally open switch comprising a make-before-break .switch combination, a pre-arming circuit including said relay and connected sequentially to the second and third transfer switch assemblies respectively when the chatter switch operates sequentially in accordance with said predetermined time sequence for cnergization of the rether including a mine detonator, a sterilizing circuit including said condenser and said detonator connected in series circuit relation, and a pre-sterilizing circuit connected to the sterilizing circuit and sequentially to the fourth and fifith transfer switch assemblies respectively when the chatter switch operates sequentially in accordance with said predetermined sequence for discharging the condenser through the detonator thereby to sterilize the armed mine through detonation thereof.

6. The device of claim 5 further characterized by comprising a disabling circuit connected through said transfer switches to be operable from said first source when the chatter switch receives a spurious impulse transmitted through the surrounding water during operation of the motor and including an electron discharge device. connected across the condenser for rendering the discharge device conducting whereby the condenser is discharged to thereby disable the mine mechanism for the remainder of the cycle.

7. A device of the character disclosed comprising, in combination, a plurality of sources of power, a pressure responsive chatter switch connected between a first of said sources of power and ground, a plurality of cam operated transfer switch assemblies having transfer switches operatively interconnected in series relationship for actuation in a predetermined time sequence, a first normally closed switch of the first of said assemblies being connected to the connection between the first source and the chatter switch, a timing motor, a plurality of switch actuating cams connected to said motor for rotation thereby at a predetermined rate to actuate said switch assemblies in said predetermined time sequence, a second normally closed switch of said first assembly being connected to a second of said sources of power, a condenser, a charging circuit for charging said condenser from said second source of power and including said second switch of said first assembly initially connecting the condenser thereto, a motor starting circuit operable from a third of said sources of power and including a pair of normally'open'contacts and the motor, a relay for closing said normally open contacts when the relay is energized, a relay circuit including a third normally closed switch of the first assembly for energizing the relay from said second source when the relay circuit is operatively energized by said first source through said first normal-- 1y closed switches in concurrence with the operation of the chatter switch in'response to a first impulse transmitted through the surrounding water, a motor running circuit operable from said third source of power and including a first normally open switch of the first of said assemblies and the motor, said third normally closed switch and said first normally open switch comprising a make-before-break switch combination, circuit closing means effective when operated for discharging said condenser through the relay, means connected electrically to said circuit closing means and to thefirst, second and third transfer switches of the transfer switch assemblies for partially operating said circuit closing means when the second transfer switch assembly operates concurrently with the chatter switch in response to a second impulse received thereby and for fully operating the circuit closing means when the third transfer switch assembly operates concurrently with operation of the chatter switch in response to the third impulse received thereby, an electroresponsive arming device, and a circuit for operating said arming device from said third source including a second pair of normally open contacts-operated by said relay and a normally open switch individual to said third transfer switch assembly.

8. A mine mechanism of the character disclosed comprising, in combination, power source means for providing operating potential for the mine mechanism, rotary means operable in unit cycles, a plurality of switch assemblies mechanically connected to said means for operation thereof in a predetermined time sequence, chatter switch means responsive, to impulses transmitted through the surrounding water, starting circuit means op eratively connected to drive said rotary means to commence the unit cycle, arming circuit means for arming the mine to render the mine adaptable for exploding, sterilizing circuit means for disabling the mine and rendering the mine incapable of exploding, said starting, arming and sterilizing circuit means being respectively connected in predetermined sequence through selected switch assemblies to said power source means as the chatter switch operates in a predetermined time sequence corresponding to the time sequence of impulse transmission, and a disabling circuit connected through all of said switch assemblies to said power source means at all 14 times during which none of the switch assemblies are operated whereby the mechanism will be disabled should a spurious impulse be received by the impulse responsive switch device.

9. A mine arming and sterilizing mechanism adapted to be actuated in response to a series of impulses received through the surrounding water in a predetermined time sequence comprising, in combination, operating potential means, a switch timer operable in unit cycles and including a plurality of switch assemblies operable in a predetermined time sequence during one cycle of operations thereof, starting circuit means operatively connected to drive said rotary means to commence a unit cycle, arming circuit means for arming the mine to render the mine adaptable for exploding, sterilizing circuit means for disabling the mine and rendering the mine incapable of exploding, said starting, arming and sterilizing circuit means being respectively connected through selected switch assemblies to be energized from said operating potential means in a predetermined time sequence corresponding to the time sequence of impulse transmission, and an impulse responsive switch device connected to said switch assemblies for causing each of the circuits to be operatively energized from said operating potential means when the impulse responsive switch operates in the predetermined time sequence.

10. A mechanism of the character disclosed for arming a mine in response to a series of impulses received through the surrounding water in a predetermined time sequence comprising, in combination, operating potential means, a switch timer operable in unit cycles and including a plurality of switch assemblies operable in a predetermined time sequence during one cycle of operations thereof, starting circuit means operatively connected to drive said rotary means to commence a unit cycle, arming circuit means for arming the mine to render the mine adaptable for exploding, said starting and arming circuit means being respectively connected through selected switch assemblies to be energized from said operating potential means in a predetermined time sequence corresponding to the time sequence of impulse transmission, and an impulse responsive switch device connected to said switch assemblies for causing each of the circuits to be operatively energized from said operating potential means when the impulse responsive switch operates in the predetermined time sequence.

11. An arming and sterilizing system for a mine comprising, in combination, a circuit for arming the mine,

device and certain ones of said plurality of switches for operating said arming circuit when additional impulses are received in the time sequence of operation of said certain ones of the switches, and means including the im- 7 pulse responsive device and certain other ones of said plurality of switches for operating said sterilizing circuit when additional impulses are received in a subsequent cycle of operations of said timing device and in the time sequence of operation of said other ones of the switches.

12. An arming and sterilizing system for a mine comprising, in combination, a circuit for arming the mine, a circuit for sterilizing the mine, a switch timing device operable in unit cycles and including a plurality of switches connected to be operated in predetermined sequence thereby in each cycle of operation, an impulse responsive device, means for setting the timing device in operation when an impulse is received by the impulse responsive device, means including said impulse responsive operating said arming circuit when a predetermined number of subsequent impulses are received in the time sequence of operation of said certain ones of the switches, and means including said impulse responsive device and certain other ones of said plurality of switches for operating said sterilizing circuit when additional impulses are received in a subsequent cycle of operations of said timing device and in the time sequence of operation of said other ones of the switches.

13. In a mine arming mechanism adapted to be set into operation by a series of impulses transmitted through the surrounding water in a predetermined time sequence, the combination of first, second and third sources of power, an arming device, circuit closing means adapted to be rendered operative in response to a voltage of predetermined value to energizably connect said device to said first power source, a control circuit connected to said circuit closing means and to said second and third sources of power for sequentially developing a first voltage and a second voltage additive to the first voltage, and time measuring means for developing said voltages in a predetermined time sequence to derive a voltage of said predetermined value and including circuit means for utilizing said derived voltage to render said circuit closing means operative at a selected time.

14. A mine arming and sterilizing mechanism of the character disclosed comprising, in combination, timing means operable in unit cycles, an arming circuit operatively connected to said means and including additive voltage means for partially activating said circuit in a first group of progressive stages at predetermined intervals of time until the mechanism has armed the mine, and a sterilizing circuit operatively connected to said first named means and including a second additive voltage means for partially activating said sterilizing circuit in a second group of progressive stages at predetermined intervals of time until the mine has been sterilized.

15. A mechanism for arming a mine in response to coded signals comprising, in combination, a circuit closing device having contacts connectable in the arming circuits of said mine for closing the arming circuits when the device is operated, a pair of grid controlled gaseous discharge devices, an electric motor, a relay having two pairs of normally open contacts, a circuit including one pair of said relay contacts for starting operation of said motor from a first source of power therefor when the relay is energized, a first switch assembly including first and second break-make switch combinations and a makebefore-break switch combination, a second switch assembly comprising a break-make switch combination, a third switch assembly comprising first, second and third make switch combinations, a voltage divider network connected to a second source of power and including a normally closed signal responsive chatter switch for elevating the potential in the network to a predetermined value in excess of the control gap breakdown potential of said discharge devices when the chatter switch is opened, a circuit including the break contacts of said make-beforebreak switch combination and connecting the relay and the main discharge path of one of said discharge devices in series across a third source of power for energizing the relay therefrom when said one of the discharge devices is rendered conducting, a circuit including the make contacts of said make-before-break switch combination and connected to said first source of power for maintaining operation of the motor therefrom when said make contacts are closed, a condenser, a circuit including the break con tacts of said second break-make switch combination for charging said condenser from said third source of power, first and second resistances connected in series across the control gap of said one of the discharge devices, a circuit including the make contacts of said second breakmake switch combination for connecting said first resistance and the main discharge path of the other of the discharge devices in series across said third source of power when the make contacts are closed thereby to develop a first voltage across said first resistance when the second discharge device is rendered conducting, a circuit including the break contacts of said first break-make switch combination for applying said predetermined potential at said network point across the control gap of said one of the discharge devices thereby to render said one of the devices conducting when the chatter switch opens, a circuit including the make contacts of said first break-make switch combination and the make contacts of the break-make switch combination of the second switch assembly for applying said predetermined potential at said network point across the control gap of said other of the discharge devices thereby to render the second discharge device conducting when the chatter switch opens while the make contacts of the second switch assembly are closed, a circuit including the make contacts of said first break-make switch combination, the break contacts of said break-make switch combination of the second switch assembly and said first make switch combination and connected to said series connected resistors for applying said predetermined potential at said network point thereacross to develop a voltage therein additive to said first voltage and suflicient to render said one of the discharge devices conducting when the chatter switch opens while said make switch combinations are closed, a circuit including said second make switch combination for discharging said condenser through the relay and said one of the discharge devices thereby to energize the relay therefrom when said one of the devices is rendered conducting and said second make switch combination is closed, a circuit including the other pair of relay contacts and said third make switch combination for operating said circuit closing device from said first source of power when said second pair of relay contacts and said third make switch combination are closed concurrently, and means driven by said motor and operatively connected to said switch assemblies for operating said first switch assembly for a first predetermined interval and for operating said second and third switch assemblies for shorter predetermined time spaced intervals respectively during said first interval as the motor operates.

References Cited in the file of this patent UNITED STATES PATENTS 1,390,768 Dorsey Sept. 13, 1921 

